Research And Implementation Of Color Adjustment Method For The Printing Machine Based On Pattern Matching

With the development of computer image processing technique,printing press control technology and computer hardware system,printing color control technology has been continuously following the footsteps of the times to achieve development.Printing industry is changing from a conventional manual-controlled mode to a digital,automated,smart workflow control.In the context of high speed printing,if products are not monitored in real time,problems like graphic defects and color missing will lead to making a large number of non-standard products,which is a great waste of printing materials and also a loss for a printing company's revenue,so it is crucial to check the quality of products on-line and to use intelligent color control system.In order to keep up with the trend of modern printing industry and cater for the demand of printing companies,this thesis is going to adopt the method that uses printing color management to analyze print image to achieve a closed-loop control over the online detection and the color management.The main contents of this thesis are as follows:First,preprocess the original images;exclude products with bigger,unclear images and other interference problems like serious displacements caused by printing equipment factors during the printing process.Through the image location algorithm,we are able to obtain a valid print image for later processing use.Second,product defect detection;printed images that have been preprocessed will be matched with standard templates based on matching graphics and text quality analysis;delimit the void area of the products and types;estimate the quality of the product graphics and text form.Third,the printing color management;analyze the color difference of good printing images and establish ink control model based on the result of the analysis to revise the ink supply and therefore,achieve color management.Through continuous production tests,the stability and reliability of the system have been greatly improved.On the basis of data accumulation and training,the precise intervention of the color management system to the printing press is gradually improved,and accordingly,the range of the color difference is gradually reduced as well.